You are Here: Home >< Maths

# Differentiation

Announcements Posted on
Why bother with a post grad course - waste of time? 17-10-2016
1. Just a little something I need clearing up...Finding out the value of x..

x^5/2 = 32

So I moved the exponent over, to make:

x = sprt 32^5

The answer is 4 but I obviously dont get that answer following my method - I thought that is how you deal with fractional exponents....?

I know it must be something simple I am forgetting :-(
2. (Original post by christinajane)
Just a little something I need clearing up...Finding out the value of x..

x^5/2 = 32

So I moved the exponent over, to make:

x = sprt 2^5

The answer is 4 but I obviously dont get that answer following my method - I thought that is how you deal with fractional exponents....?

I know it must be something simple I am forgetting :-(
If you have then this must mean that . Which is not .

Do you remember your indices laws?

If you have this is .
3. (Original post by christinajane)

x^5/2 = 32
Why don't you do it step by step?

is

So tex]x^{5/2} = (\sqrt{x})^5 = 32[/tex].

First step: move the 5 over. .

Now you're left with a simple equation: . Hence, squaring both sides: .

i.e: you need to square root four to get 2.
4. (Original post by Zacken)
If you have then this must mean that . Which is not .

Do you remember your indices laws?

If you have this is .

Hello Zacken,

I thought that when an exponent crosses the = sign it becomes a sqrt

like

x^2 = 4

so

x = sprt 4

x = 2

I thought the same thing happened with fractional exponents crossing the = sign..

so I thought in this case

x^5/2 = 32

x = sprt 32^5

on so on but I know its wrong....
5. (Original post by Zacken)
Why don't you do it step by step?

is

So tex]x^{5/2} = (\sqrt{x})^5 = 32[/tex].

First step: move the 5 over. .

Now you're left with a simple equation: . Hence, squaring both sides: .

i.e: you need to square root four to get 2.

Basically you just flip the fractional exponent when it crosses the = sign?

its these little things i keep forgetting!!
6. (Original post by christinajane)
Hello Zacken,

I thought that when an exponent crosses the = sign it becomes a sqrt

like

x^2 = 4

so

x = sprt 4

x = 2

I thought the same thing happened with fractional exponents crossing the = sign..

so I thought in this case

x^5/2 = 32

x = sprt 32^5

on so on but I know its wrong....
This is the rule: whenever you have an exponent crossing the = sign, you flip the the exponent over.

So if you move a 2 over, it becomes 1/2. i.e: means .

If you move over, it becomes 2. i.e: .

If you move over, it becomes .

If you move over, it becomes .
7. Thank you!!

Indices and surds get me everytime!! Its my most looked at chapters in the C1 book and on mymaths!!
8. (Original post by christinajane)
Thank you!!

Indices and surds get me everytime!! Its my most looked at chapters in the C1 book and on mymaths!!
It'll come with practice.

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: April 17, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

### How does exam reform affect you?

From GCSE to A level, it's all changing

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read here first

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams